By Hilary Corrigan

Triplicate staff writer

Doctors at California Pacific Medical Center in San Francisco plan to complete a six-hour surgery today to repair the scalp of a 70-year-old hiker attacked by a mountain lion last week.

Jim Hamm remains in the intensive care unit, but has been upgraded from critical to stable condition, said hospital spokesman Kevin McCormack.

Hamm has also shown improvement a lower fever and decreased swelling from an infection that he developed from bacteria common to cats. Doctors had administered penicillin and the infection had not reached any vital organs.

Wednesday's microvascular surgery will entail stitching muscle and skin from Hamm's back to his skull.

andquot;To replace all the flesh that was torn away,andquot; McCormack said, noting the exposed bone.

While complicated and painstaking, the surgery is not considered risky, McCormack said. Doctors will monitor Hamm for at least five days to make sure that the blood vessels bond.

It will be Hamm's second surgery resulting from the attack. Besides many stitches to his face, the Fortuna man underwent a skin graft to repair his scalp at Mad River Community Hospital in Arcata.

Over the weekend, he was flown to the larger facility in San Francisco where doctors could better monitor infections from his wounds.

A mountain lion attacked Hamm on Jan. 24 as he walked Brown Creek Trail with his wife at about 3 p.m. in Prairie Creek Redwoods State Park.

Nell Hamm, 65, fought the cat with a tree branch until it eventually released her husband. The couple walked about a quarter of a mile to the trailhead, where park staff and a work crew called for an ambulance.

Hamm suffered deep cuts, bites and tissue damage to his head, face, torso and arms.

andquot;He was pretty badly mauled,andquot; McCormack said.

Reach Hilary Corrigan at